1. Field of the Invention
The present invention relates generally to overflow safety switches for condensation producing equipment and, more particularly, to a device for installing an overflow safety switch to the side wall of a drain pan in HVACR equipment.
2. Discussion of the Related Art
In various systems and equipment, there is a need to transfer and/or drain liquid to another location. For example, in air conditioning and refrigeration systems, condensation naturally occurs as warm, humid air passes over the exterior of the evaporator coil. Typically, the condensation drips from the evaporator coil into a condensate collection pan positioned below the evaporator coil. From the collection pan, the liquid condensate is directed through a drain line that leads to a safe discharge location, such as the exterior of a building.
Occasionally, problems can occur as a result of a failure in the normal liquid transfer or drainage system. For instance, the primary condensate collection pan in an air conditioner unit, usually made of metal materials, is susceptible to rust and corrosion. This can lead to a leak developing in the primary collection pan, causing water damage to the area below the unit. Additionally, mildew and other microbial growths, combined with dust and other particulate, accumulate in the condensate pool. Over time, this accumulation can eventually cause the drain line to become clogged. When this happens, the continually produced condensate fills within the primary condensate collection pan and eventually overflows. The overflow of condensate from a continuously running HVAC unit can cause extensive and costly damage to the interior of a building or home. This is a common problem that is well known in the industry.
To prevent overflow of the primary condensate collection pan, most building codes require a safety shut-off switch to be installed in the drain pan. The shut-off switch senses water accumulation in the primary pan and, when the water level reaches a predetermined height that is well below the height of the side walls of the pan, the shut-off switch disables the HVAC system, thereby preventing further condensate accumulation and overflow of the primary pan. A secondary or emergency overflow pan is usually installed below the primary drain pan as an additional precaution and is sized, configured and positioned to catch water that might overflow the primary condensate collection pan. This emergency overflow pan can also be fitted with a shut-off switch and/or a drain line connection.
In most instances, the overflow safety switch is mounted to the side wall of the drain pan with the use of a metal clip that has a horizontal plate, a vertical plate and an inverted U-shaped portion that is structured and disposed to slip over the top edge of the drain pan and slide down the inner and outer surfaces of the drain pan wall in frictional engagement therewith. A screw is typically used for tightly securing the clip onto the wall of the drain pan. Specifically, a screw passes through the vertical plate of the clip and at least partially into the outer surface of the drain pan wall. The overflow safety switch is attached to the horizontal plate of the mounting clip to support the overflow switch vertically within the drain pan. More particularly, the overflow safety switch has an upper tubular portion or stem that has exterior screw threads. This upper threaded stem is fitted through a circular opening in the horizontal plate and held in place by one or more nuts on the threaded stem. When the clip is installed to the side wall of the drain pan, the overflow safety switch needs to be adjusted to the lowest point in the pan (i.e., the floor of the pan) by threadably manipulating the one or more nuts on the stem. Once the mounting clip is fixed to the side wall of the drain pan, and the overflow switch is in the proper adjusted position, the one or more nuts are tightened against the horizontal plate of the clip to hold the overflow switch in the proper operative position relative to the floor of the drain pan. An example of this type of mounting clip and overflow safety switch arrangement is described and illustrated in Patent Application Publication No. US 2005/0166613 to Oakner et al.
In many instances, due to the extra work needed for properly adjusting the position of the overflow safety switch relative to the mounting clip and bottom of the drain pan, the installer will simply attach the clip and overflow switch to the side wall of the drain pan with the switch held at a position that is not low enough to sense a rise water level in the drain pan. Thus, the switch is unable to perform its intended function and the rising water level will eventually lead to an overflow of the drain pan.
Moreover, the manner in which the overflow switch is attached through the circular opening in the horizontal plate requires removal of the entire combined assembly of the mounting clip and overflow switch from the drain pan for purposes of replacement or repair of the overflow switch. Thereafter, installing a new (i.e., replacement) overflow switch on the wall of the drain pan requires another tedious adjusted procedure which, as noted above, is often overlooked. It can therefore be appreciated that the currently and extensively used mounting clip and overflow safety switch arrangement has significant limitations, including the need for time consuming and tedious installation, replacement and adjustment that can result in improper installations that render the overflow switch inoperative and thereby causing drain pan overflows and costly damage.
Accordingly, there remains a need for an improved mounting device and assembly for easily and efficiently securing an overflow safety switch to the side wall of a condensation collecting drain pan as found in HVACR equipment, and wherein the overflow switch can be easily and quickly adjusted to the proper operative position, and further wherein the overflow switch can be easily removed and replaced without removing the mounting clip from the drain pan.